ABSTRACT
@#Objective To develop and verify a qPCR method for the qualitative and quantitative analysis of residual host DNA in human rabies vaccine(Vero cells) stock solution.Methods The qPCR standard curve was established by using the Vero cell DNA quantitative national standard,and the residual host DNA was extracted using magnetic beads.The specificity,repeatability,intermediate precision,accuracy and durability of the method were verified,and the linear range and limit of quantification were determined.The residual DNA of three batches of human rabies vaccine(Vero cells) stock solution was quantitatively analyzed and the fragment size was qualitatively analyzed by using this method.Results The correlation coefficients(R~2) of Vero cell DNA quantitative national standard amplification standard curve were all more than 0.99 by qPCR,and the quantitative range was 0.3 pg/mL～30 ng/mL.The method showed good specificity and repeatability.In the verification of intermediate precision,accuracy and durability,the relative standard deviations(RSD)of detection results of the samples were all less than 10%.The residual DNA content of Vero cells in three batches of stock solution was 0.20～0.77 ng/dose,which met the relevant standard of Chinese Pharmacopoeia(Volume Ⅲ,2020edition).The residual DNA fragments greater than 154 bp accounted for 52%～63%.Conclusion The developed qPCR method for the detection of residual DNA in human rabies vaccine(Vero cells) stock solution had good specificity,repeatability,intermediate precision and durability,and qualitatively and quantitatively analyzed the residual DNA rapidly and accurately,which was of great significance for improving the detection and control of residual DNA content in the production process and final product of human rabies vaccine(Vero cells).